🚨 Build a Student Grade Manager in Java That’ll Blow Your Mind! (No Frameworks Needed!) 🚀

“Think Java is boring? Wait till you build a full-blown Student Grade Management System with just Swing and JDBC. No Spring, No JavaFX — just pure power!”

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🧑‍🎓 What Are We Building?

A desktop application that lets you:

✅ Add new students
✅ Update existing grades
✅ Delete student records
✅ View all data in a table

All using Java Swing and SQLite (JDBC) — no third-party libraries.

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🔧 Technologies Used

Tool	Purpose
Java	Language
Swing	GUI (Graphical User Interface)
SQLite	Lightweight database
JDBC	Database connectivity

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🏗️ Project Structure

StudentGradeApp/
├── Student.java          # Model class
├── DatabaseHelper.java   # Database utility
├── StudentDAO.java       # Data Access Object
├── StudentApp.java       # GUI (main class)
└── students.db           # SQLite database

📄 1. Student.java – The Model

public class Student {
    private int id;
    private String name;
    private double grade;

    public Student(int id, String name, double grade) {
        this.id = id;
        this.name = name;
        this.grade = grade;
    }

    // Getters and setters
    public int getId() { return id; }
    public String getName() { return name; }
    public double getGrade() { return grade; }

    public void setId(int id) { this.id = id; }
    public void setName(String name) { this.name = name; }
    public void setGrade(double grade) { this.grade = grade; }
}

🔍 Explanation:
This class holds student data. It’s a simple POJO (Plain Old Java Object) with fields, a constructor, and getters/setters.

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🔌 2. DatabaseHelper.java – SQLite Connector

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DatabaseHelper {
    private static final String URL = "jdbc:sqlite:students.db";

    public static Connection connect() throws SQLException {
        return DriverManager.getConnection(URL);
    }
}

🔍 Explanation:
This class holds student data. It’s a simple POJO (Plain Old Java Object) with fields, a constructor, and getters/setters.

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🔌 2. DatabaseHelper.java – SQLite Connector

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DatabaseHelper {
    private static final String URL = "jdbc:sqlite:students.db";

    public static Connection connect() throws SQLException {
        return DriverManager.getConnection(URL);
    }
}

🔍 Explanation:
This static utility returns a database connection using JDBC.

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💾 3. StudentDAO.java – All DB Operations

import java.sql.*;
import java.util.*;

public class StudentDAO {

    public static void createTable() {
        String sql = "CREATE TABLE IF NOT EXISTS students (id INTEGER PRIMARY KEY, name TEXT, grade REAL)";
        try (Connection conn = DatabaseHelper.connect(); Statement stmt = conn.createStatement()) {
            stmt.execute(sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void insertStudent(Student student) {
        String sql = "INSERT INTO students(id, name, grade) VALUES(?, ?, ?)";
        try (Connection conn = DatabaseHelper.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
            pstmt.setInt(1, student.getId());
            pstmt.setString(2, student.getName());
            pstmt.setDouble(3, student.getGrade());
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static List<Student> getAllStudents() {
        List<Student> list = new ArrayList<>();
        String sql = "SELECT * FROM students";
        try (Connection conn = DatabaseHelper.connect(); Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery(sql)) {
            while (rs.next()) {
                list.add(new Student(rs.getInt("id"), rs.getString("name"), rs.getDouble("grade")));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return list;
    }

    public static void updateStudent(Student student) {
        String sql = "UPDATE students SET name = ?, grade = ? WHERE id = ?";
        try (Connection conn = DatabaseHelper.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
            pstmt.setString(1, student.getName());
            pstmt.setDouble(2, student.getGrade());
            pstmt.setInt(3, student.getId());
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void deleteStudent(int id) {
        String sql = "DELETE FROM students WHERE id = ?";
        try (Connection conn = DatabaseHelper.connect(); PreparedStatement pstmt = conn.prepareStatement(sql)) {
            pstmt.setInt(1, id);
            pstmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

🔍 Explanation:

• createTable() creates the table if it doesn’t exist.
• insertStudent() adds a new student.
• getAllStudents() fetches all records.
• updateStudent() updates name and grade.
• deleteStudent() removes by ID.

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🖼️ 4. StudentApp.java – GUI Logic

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.*;
import java.util.List;

public class StudentApp extends JFrame {
    private JTextField idField, nameField, gradeField;
    private JTable table;
    private DefaultTableModel model;

    public StudentApp() {
        super("Student Grade Manager");

        // Input Form
        JPanel form = new JPanel(new GridLayout(4, 2));
        idField = new JTextField();
        nameField = new JTextField();
        gradeField = new JTextField();

        form.add(new JLabel("ID:"));
        form.add(idField);
        form.add(new JLabel("Name:"));
        form.add(nameField);
        form.add(new JLabel("Grade:"));
        form.add(gradeField);

        JButton addBtn = new JButton("Add");
        JButton updateBtn = new JButton("Update");
        JButton deleteBtn = new JButton("Delete");

        form.add(addBtn);
        form.add(updateBtn);

        // Table
        model = new DefaultTableModel(new String[]{"ID", "Name", "Grade"}, 0);
        table = new JTable(model);
        JScrollPane tablePane = new JScrollPane(table);

        // Layout setup
        setLayout(new BorderLayout());
        add(form, BorderLayout.NORTH);
        add(tablePane, BorderLayout.CENTER);
        add(deleteBtn, BorderLayout.SOUTH);

        // Button Actions
        addBtn.addActionListener(e -> addStudent());
        updateBtn.addActionListener(e -> updateStudent());
        deleteBtn.addActionListener(e -> deleteStudent());

        table.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {
                int row = table.getSelectedRow();
                idField.setText(model.getValueAt(row, 0).toString());
                nameField.setText(model.getValueAt(row, 1).toString());
                gradeField.setText(model.getValueAt(row, 2).toString());
            }
        });

        loadTable();

        setSize(500, 400);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }

    private void loadTable() {
        model.setRowCount(0);
        List<Student> students = StudentDAO.getAllStudents();
        for (Student s : students) {
            model.addRow(new Object[]{s.getId(), s.getName(), s.getGrade()});
        }
    }

    private void addStudent() {
        try {
            int id = Integer.parseInt(idField.getText());
            String name = nameField.getText();
            double grade = Double.parseDouble(gradeField.getText());
            StudentDAO.insertStudent(new Student(id, name, grade));
            loadTable();
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "Invalid input.");
        }
    }

    private void updateStudent() {
        try {
            int id = Integer.parseInt(idField.getText());
            String name = nameField.getText();
            double grade = Double.parseDouble(gradeField.getText());
            StudentDAO.updateStudent(new Student(id, name, grade));
            loadTable();
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "Invalid input.");
        }
    }

    private void deleteStudent() {
        try {
            int id = Integer.parseInt(idField.getText());
            StudentDAO.deleteStudent(id);
            loadTable();
        } catch (Exception e) {
            JOptionPane.showMessageDialog(this, "Invalid input.");
        }
    }

    public static void main(String[] args) {
        StudentDAO.createTable();
        new StudentApp();
    }
}

🔍 Explanation:

• GUI has 3 fields: ID, Name, Grade.
• Buttons trigger add, update, delete actions.
• Table reflects live changes.
• Click on a table row to load data into the form.

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🧪 Sample Workflow

1. Run the app
2. Enter student info → click Add
3. Select row → edit → click Update
4. Click Delete to remove a record

✅ All actions instantly reflect in the table.

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🎁 Bonus Ideas

• Add a search box to filter students
• Add input validation (e.g., name must be letters)
• Export data to CSV or Excel
• Use JavaFX for a modern UI